Study on static and fatigue behaviors of carbon fiber bundle and the statistical distribution by experiments

Abstract

In this paper, the static, tension–tension fatigue, and residual strength behaviors of carbon fiber bundle have been investigated using experimental methods. The corresponding mechanical models and statistical distribution regulations have also been established based on the experimental data. The test results indicate that the test section length of fiber bundle had a marked effect on the static strength, which decreased with the increase of length. A two-parameter Weibull distributional function was used to describe the distribution of static strength. Furthermore, the S-N curve was obtained by a new segmented function to reflect the changing of fatigue life against stress levels. The experimental results of residual strength show that there was an abnormal tendency, which increased first and decreased later as the increase of cyclic number, for the residual strength of carbon fiber bundle in both tested stress levels 87% and 80%, respectively. Therefore, a new model for the residual strength was put forward and the good agreement between the fitting curves and experimental was obtained.